Study of the interconversion of polyaniline oxidation states by optical absorption spectroscopy

Preparation and characterization of castor oil‐based polyurethane/poly(o‐methoxyaniline) blend film

“…The undoped PU/ POMA shows a peak at 625 nm, characteristic of POMA, corresponding to molecular exciton transition, as described in the literature. 21 The band at 390 nm and the free carrier tail above 600 nm, related to the doping process, are assigned as polaron bands that are responsible for the polymer conductivity. The free carrier tail is indicative of secondary doping effects, which result from a more extended chain conformation, 22 allowing a more delocalized polaronic band.…”

Facile and novel route for preparation of nanostructured polyaniline (PANi) thin films

“…The UV-Vis-NIR absorption spectrum of PANi film shows two sharp absorptions: one with maximum at 441 nm (&3.4 eV) p-p* transition of benzenoid ring and another at 652 nm (&2.04 eV) corresponding to molecular exciton transition. This is due to the oxidation states of the PANi (de Albuquerque et al 2004).…”

Nanostructured polyaniline thin films as pH sensing membranes in FET-based devices

“…N-PANI exhibited a strong absorption band at 740 nm due to the polaron band characteristic of doped polyaniline [18]. The band at 340 nm is ascribed to the -* transitions of the benzenoid rings and the band at 430 nm can be assigned to the partial oxidation state of the PANI (ES) [4,19]. UV-Vis spectra collected for solutions of N-PANI in different pH values reveal the characteristic isosbestic point (i.p.)…”

“…Polyaniline (PANI) is a well-known semiconductor polymer that has attracted attention in the scientific and engineering fields especially for application in chemical sensors [1], light emitting diode [2] and biosensors [3] due to its chemical environmental stability, facile synthesis, low cost, and possibility of control over electrical properties upon reversible doping of the polymer backbone [4]. One of the most exciting applications of the polyaniline lies in the application as active material for sensing devices [5][6][7].…”